The present invention relates generally to synchronous machines and more particularly to converting a synchronous generator to a synchronous condenser.
Synchronous generators driven by turbines are commonly used by power utilities to produce electrical energy. Often after many years of use, power utilities will retire or decommission synchronous generators from use as power generation units. In some cases, it is desirable to use these retired synchronous generators as synchronous condensers to generate reactive power or absorb reactive power. As a general proposition, a retired synchronous generator needs to be decoupled from the turbine that drove it when being used as a synchronous condenser. In order for the decoupled generator to be used as a synchronous condenser, it needs to be brought to operational speed. Typically, dedicated means such as a starting motor attached to the shaft of the rotor of the generator is used to bring the generator up to operational speed. Assembling the starting motor to the rotor can be time consuming. In addition, the starting motor needs to be designed to withstand any operational event (e.g., electrical faults in the motor or synchronous condenser, overspeed events, shaft failures, and general malfunctions) that a normal motor might experience even though it will be in service for only a short time period.